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Alpine MRX-M55

Mono subwoofer amplifier — 550 watts RMS x 1 at 2 ohms

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  • Alpine MRX-M55

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  • Alpine MRX-M55

  • Alpine MRX-M55

  • Alpine MRX-M55

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Our take on the Alpine MRX-M55

by Buck Pomerantz
Alpine

My system has plenty of power. Who needs an amp?

You might think you don't need an amp because you have a 400-watt system in your car, or because your new stereo puts out 50 watts a channel. But those are peak wattage ratings, which may boil down to 15 or 20 watts per channel, using the more realistic RMS rating. An amp sends your speakers the power they need to deliver your music with clarity and impact, whether you're using factory speakers or high-performance components. And low-frequency reproduction requires lots of power, so an amp is an absolute must if you're adding a sub to your system.

Alpine Authorized Online Dealer

Digital technology that sounds perfect

Alpine's X-Power MRX-M55 mono amplifier uses the latest amp technology to play your music loud and clean without taking up much space. And this amp employs some of the same circuitry developed for Alpine's top-of-the-line PDX digital amps, so it'll bring exceptional sound to almost any ride.

Big power for big bass

The MRX-M55 puts out up to 550 watts RMS to your subwoofer system, so you can fill your listening space with plenty of bass. And it'll even operate safely with a 1-ohm load, making it useful in a variety of sub system installations. Onboard low-pass and subsonic filters let you get the best sound out of your setup, while a bass boost helps to fatten up the sound if you need it.

Keep the music playing

A power management system optimizes the amp's performance and keeps the music playing, even when you're pushing it hot and hard for a long time. Speaker-level inputs with an automatic turn-on feature simplify system hook-up.

MRX-M55 control panel
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Highlights:

  • mono subwoofer car amplifier
  • 350 watts RMS x 1 at 4 ohms (550 watts RMS x 1 at 2 ohms)
  • 400 watts RMS x 1 at 1 ohm
  • CEA-2006 compliant
  • variable low-pass filter (50-400 Hz, 24 dB/octave)
  • variable bass boost (0-12 dB at 50 Hz)
  • variable subsonic filter (5-30 Hz, 24 dB/octave)
  • optional remote level control (RUX-KNOB)
  • Class D amp with MOSFET power supply
  • preamp and speaker-level inputs
  • preamp outputs
  • fuse rating: 30A x 2
  • 8-gauge power and ground leads recommended — wiring and hardware not included with amplifier
  • 9-15/16"W x 2-5/16"H x 9-1/16"D
  • warranty: 1 year
  • Our 60-day money-back guarantee

Hands-on research from the Crutchfield Labs (what are the Labs?)

Features and Specs
Performance
RMS Power Output (Watts x Channels) 350 x 1
Peak Power Output (Watts x Channels) 1100 x 1
Power at 2 Ohms (Watts x Channels) 550 x 1
Bridged Power (Watts x Channels) N/A x
Minimum Impedance Bridged ---
Minimum Impedance Unbridged 1
Best Frequency Response 5-400 Hz Hz
THD at Rated RMS Power 1%
Signal to Noise Ratio 90 dB
Input Voltage 14.4v
Features
Amplifier Class D
Low-Pass Crossover Frequency 50-400 Hz
Low-Pass Slope (dB/octave) 24 dB/oct
High-Pass Crossover Frequency N/A
High-Pass Slope (dB/octave) N/A
Bass Boost 0-12 dB
Bass Boost Frequency 50 Hz
Fan Cooled No
Fuse Rating 60
Speaker Level Inputs Harness
Preamp Outputs 1 pair
Width (inches) 9-15/16
Height (inches) 2-5/16
Depth (inches) 9-1/16
Parts Warranty 1 Year
Labor Warranty 1 Year
Product Research
What's in the box?

Download owner's manual

  • Mono amplifier with two 30A fuses installed
  • Left plastic terminal cover
  • Right plastic terminal cover
  • 4 Terminal cover screws (M3 x 10mm)
  • 4 Self-tapping screws (M4 x 20mm)
  • 2.5mm Allen wrench
  • 7" Speaker-level input harness
  • Owner's Manual (Eng/ Fren/ Span)
  • Warranty sheet
  • Online registration card
  • Alpine Verification Certificate

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team — they open the box, verify contents, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.

Features
Controls
Connections

Features

MRX Amplifier Design: Class-D amplifiers boast higher efficiency, produce less heat, and draw less current than traditional Class-AB amps. The MRX series benefits from the technology trickledown from Alpine's more expensive PDX amps, including Direct FET final outputs, thermal management processor, 6-Layer Glass Epoxy PC Board; combining to create a high-end sound quality without the bulky heat sinks required by most amps in this power class.

STAR Topology: Alpine's unique STAR (Signal Transit for Accurate Response) Circuit PCB design provides a single common ground for all amp sub-blocks, preventing ground interference and minimizing internal noise.

Power Management Processor: The multi-stage Power Management Processor continuously monitors component temperatures throughout the amplifier and decreases power output if anything gets too hot. When playing music under heavy loads for long periods, the circuit automatically reduces power output slightly at first, and then further in a second stage if necessary. This two stage approach provides an interruption free listening experience.

CEA 2006 Compliant: The MRX-M55's power ratings are measured according to the Consumer Electronics Association CEA-2006 standards. These standards allow you to accurately compare the rated power output of all CEA 2006-compliant amplifiers, even different brands. Manufacturers who adhere to the standards can display the CEA 2006 logo on their products and packaging. The power output is measured from 20 Hz to 400 Hz using a 14.4 volt power supply with no more than 0.01% THD+N:

  • 4-ohm: 350 watts
  • 2-ohm: 550 watts
  • 1-ohm: 400 watts

Signal-to-Noise: When measured under CEA-2006 conditions (reference 1 watt into a 4-ohm load) the signal to noise ratio is 90 dBA. Measured at the rated power output S/N is 114 dB.

Verification Certificate: The amplifier comes with a certificate that lists the RMS power output measured from that specific amplifier. It also lists the model number, serial number, test date, and the test conditions (voltage and impedance).

Auto Turn On: When using the speaker level inputs the X-Power amplifiers automatically turn on when voltage is detected on the signal inputs, making them an easy factory system upgrade.

Low Output Impedance: With low output impedance, the MRX-M55 outputs tightly controlled bass, with a damping Factor rated at greater than 1000.

LED: The top panel LED power indicator glows blue when the amplifier is turned on.

Controls

Gain: The MRX-M55's gain is set according to the level of the incoming signal. The line-level input gain setting is continuously variable from 100 mV to 4.0V; the speaker-level input gain setting is continuously variable from 250 mV to 10.0V.

Crossover: The low-pass crossover point is continuously variable from 50 to 400 Hz and the slope is 24 dB/oct; the crossover cannot be bypassed.

Subsonic Filter: The amp also has a 24 dB/oct subsonic filter, continuously variable from 5 to 30 Hz.

Bass EQ: Bass boost can be applied to the subwoofer output; it's variable from 0 to +12 dB and centered at 50 Hz.

Connections

Power/Ground/Remote: The MRX-M55 features set-screw terminals for the Power, Ground and Remote Turn-on inputs. The Power and Ground terminals will accommodate up to 4 gauge wire (Alpine recommends 4 gauge for cable runs over 3'), the Remote Turn-on terminal will accept up to 8 gauge wire.

Speaker Output: The speaker outputs terminal is also set-screw terminals and will accept up to 8 gauge wire.

Line Input/Output: Line level RCA is the preferred input connection. The full range stereo line output allows easily adding another amp without running a second set of cables.

Speaker Level Input: Use the included speaker level input harnesses if the connected radio has no preamp outputs.

Fuses: The amp is protected by two chassis mounted 30-amp ATO fuses.

Remote Bass Control (optional): Alpine's RUXKNOB wired remote (sold separately), connects to the amp's RJ-25 Remote Bass Control jack, and offers control of the subwoofer output level from the front of your vehicle. The linear attenuation can be adjusted from 0 to -20dB.

 
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Alpine MRX-M55 Reviews

Average Customer Review:

14 people say:

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5 out of 5

Power house

Written By Jimmy, Greenfield on Wednesday, October 08, 2014
Crutchfield Customer Review (What's this?)
 
Small size but powerful amp , very reliable, I travel for hours daily and have the tunes going the whole time .
Pros:
Compact size , very powerful , tons of adjustment .
Cons:
None
Was this review helpful?    Yes | No
 
5 out of 5

Excellent for driving my 10"

Written By Samuel L, Dublin, CA on Wednesday, September 24, 2014
Crutchfield Customer Review (What's this?)
 
Plenty of power to drive a dual voice coil 10" in a sealed enclosure. Gain is @ 50% and it sounds great! Foot print of amp is small and easy to place in my trunk.
Pros:
Efficient, great value for the money. Crutchfield advisors guided me to this amp, they where patient and answered all my questions.
Cons:
none
Was this review helpful?    Yes | No
 
5 out of 5

alpine mrx m55

Written By anonymous, Somewhere, USA on Saturday, September 20, 2014
Crutchfield Customer Review (What's this?)
 
Good amp. No issues so far
Pros:
sounds clean
Cons:
None so far
Was this review helpful?    Yes | No
 
5 out of 5

Great Amp

Written By joshua L, corpus christi, TX on Sunday, August 31, 2014
Crutchfield Customer Review (What's this?)
 
Great Amp pretty small fits right under sit in a 09 Silverado single cab and delivers great clean power birth sheet was 592W at 2 ohms
Pros:
great size and power
Cons:
none
Was this review helpful?    Yes | No
 
5 out of 5

Great amp

Written By Stephen b., Coaling on Wednesday, August 20, 2014
Crutchfield Customer Review (What's this?)
 
So far so good. Real nice compact size. Give you everything you need .
Was this review helpful?    Yes | No
 
5 out of 5

MRX-M55

Written By Jack, Augusta, GA on Wednesday, July 02, 2014
Crutchfield Customer Review (What's this?)
 
Great amp. It's paired with a 10" R series sub, and it hits hard and tight.
Pros:
Crossover and eq adjustments
Was this review helpful?    Yes | No
 
5 out of 5

clean

Written By kungfucious, Carlsbad, CA on Saturday, June 28, 2014
Crutchfield Customer Review (What's this?)
 
Works perfect, big power, small amp :-)
Was this review helpful?    Yes | No
 
5 out of 5

Power to the sub

Written By RMJ, Fredericksburg,VA on Tuesday, June 24, 2014
 
This amp give the sub that awesome kick so you know it's there.
Pros:
Neat little powerhouse.
Cons:
None
Was this review helpful?    Yes | No
 
5 out of 5

Powerful

Written By Jodyd, Louisiana on Tuesday, October 22, 2013
Crutchfield Customer Review (What's this?)
 
I bought this amp to replace my alpine mrp-m500 (a friend wanted to buy it from me). It has a little more power not sure if it's dramatically more though. It plays very clear. It is definitely an upgrade do to the ability of being able to add a remote, the subsonic setting, and 50 more rms watts. The size is also smaller, I was very surprised when I unboxed it. I have it pushing an alpine type r 10" in a ported box in my 2012 super crew f150. I'm definitely under powering the sub but it still sounds awesome clean sound go alpine!
Pros:
Small, powerful, flexibility in settings
Cons:
None
Was this review helpful?    Yes | No
 
5 out of 5

more then enough!!

Written By Mark H, Cincinnati, OH on Tuesday, September 17, 2013
Crutchfield Customer Review (What's this?)
 
I purchased 2 of these for 3 subs. 2 10in dvc for 1 and being 1ohm stable makes for great power to feed these subs.They've never hit so hard. And the other amp i purchased with the seprate gain contol knob to feed 1 400w dvc. All subs are JBL. there is no substitute. Very impressed with both amps.Neither 1 runs hot. customer service with brooke was great. She even tryed to save me money.
Pros:
Very powerful. Like the connection style better then the older models. Makes for easier and cleaner install.
Cons:
Its not really a con nor a complaint. but when buying 2 of the same amps. The date of birth on 1 says 595 watts and the other says 623 watts. its just one of those odd and curious whys? but it does also say 550min.
Was this review helpful?    Yes | No
 
5 out of 5

606 watts @ 2ohms birth sheet

Written By bman, OK on Friday, April 26, 2013
Crutchfield Customer Review (What's this?)
 
Easy install and setup. Only pushing a single DVC 10" Stype and it doesn't break a sweat.
Pros:
plenty of power
Cons:
none so far
Was this review helpful?    Yes | No
 
5 out of 5

it pounds

Written By badboyb, Given, WV on Monday, April 22, 2013
Crutchfield Customer Review (What's this?)
 
This amp will handle pushing dvc subs and is 1 ohm stable ! Nice
Pros:
Easy to hook up.
Was this review helpful?    Yes | No
 
4 out of 5

575rms@2ohm birth sheet

Written By meNurma, ohio on Monday, July 02, 2012
Crutchfield Customer Review (What's this?)
 
as title states birth sheet claims 575rms @2ohms thats kinda disapointing as Alpine states on there website "Each amp comes with their very own verification certificate documenting its actual power output exceeds the rating by a wide margin" Umm 25 watts more isn't a wide margin to me. I have the gain almost all the way up and also using the OPTIONAL bass knob control and it's not hitting as hard as i would like but that could be from multiple problems bad amp or just simply needs tuned better etc etc. My lights seem to not dim that much i'm running a OEM 120amp alt and a Optima yellow top as my main car battery that's it. Hooked up to one Alpine Type R 4th gen wired @2ohms in a Sound Ordnance sealed .95ft box filled with polyfill
Pros:
clean power , small footprint
Cons:
bass knob not included , 1 year warranty unlike other brands with 2 years in this price range
10 out of 16 people found this helpful
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5 out of 5

Nice Amp!

Written By Joey, Clarksville, Md on Friday, June 22, 2012
Crutchfield Customer Review (What's this?)
 
Very nice amp. Using this amp to power a 15" sub in a sealed box. Plenty of power to drive it. Alpine sent out a verification certificate which shows actual output power(RMS) at 630 watts at 2 ohms. Sound quality is very clean. Cool running amp also. I have had this amp only a few weeks , but so far so good...





Pros:
Size, power, cost and clean sound...
10 out of 10 people found this helpful
Was this review helpful?    Yes | No
 

2 questions already asked

I've recently bought this amp and a family friend and I will be installing it ourselves. He's very familiar with car audio so I'm not concerned with the process. My question is, what gauge of wire would work best for this amp? And do different kits provide a different sound quality or do they all pretty much supply the same thing? [ DaveJ  Aug 02, 2014 ]
8 answers
  • Hi David E - we probably don't know each other but our vendor asked me to answer your questions so for what it's worth here you go: Q: What gauage wire? A: That depends. How far is the +12V source? In a typical vehicle the run is less than 20 feet so assuming the only device connected to the power lead is this amplifier then the size Alpine recommends is fine. I just happened to have enough 8g. on hand and installed this model in a Tacoma under the rear jump seats. Q: Kits vs SQ? A: Copper is copper so as long as the wire is the correct gauge there should not be a significant difference from one brand to the next. Kits usually include RCA type signal cables so this is where price can make a difference. Stay away from the budget kits that use little or no shielding and flimsy RCA connectors. You didn't ask but I'll offer this as advice for your installation. Grounding is more important than most folks understand. Use at least the same gauge wire as the battery lead and plan the mounting location out to keep the ground lead to a reasonable minimum - one or two feet if possible. Larger wires need proper crimp tools to attach the right type of connetor like a ring lug and then make sure to bolt the lug to bare metal and cover the area with silicone or spray paint to prevent rust. Hope this helps. Scott [ Scott   Aug 04, 2014 ]
  • 4 gauge or 8 gauge , 4 gauge I believe it runs better and make sure you have a really really good ground, a lot of kits are the same just make sure you get the better gauge! [ BRAD   Aug 04, 2014 ]
  • I used 4 ga for power, 8 ga for ground, and 12 ga for my subwoofer. Everything works and sounds great. The power wire was bought as a kit with an inline fuse and RCA cables. [ MARK W   Aug 04, 2014 ]
  • I bought an 8 gauge amp kit locally, I think it was a Rockford Fosgate kit. They price matched it to online so it wasn't too expensive. As long as you stick with a name brand, you'll be fine. [ Charles   Aug 09, 2014 ]
  • I would use at least a 8 gauge or bigger power and ground wire, i used 4 guage. And yes you are gonna want a better quality install kit, because lower quality kits can cause unwanted noise in your system. You really need to pay attention to the RCA cables that go from the head unit to the amp that is where you are going to want a higher quality cable. Make sure to use at least a 12 guage wire from your amp to speakers, anything smaller can possibly cause your amp to shut down . By the way you should be very pleased with this amp, i have it pushing a single 12" alpine type R and it sound very good, almost hits harder than the 2 kicker 12" i use to have. Anyways good luck and i hope this helps [ Kevin   Aug 04, 2014 ]
  • 4 gauge power wire with big in line fuse,4 gauge ground ,make sure the ground wire is as short as possible,depending on the speaker 8 to 12 gauge for the speaker wire, remote turn-on you can use a 16 gauge is fine :-) [ GREG   Aug 04, 2014 ]
  • Your wire gauge depends upon the length of wire you plan on using. For instance a short run (couple feet)you could get away with 8 or 6 gauge. A longer run (several feet) would require bigger wire like 4 or 2 gauge. The bigger the wire the easier it is for the amp to obtain the power it needs and the amp with also run cooler and more efficient. Stay away from cheap install kits, often times the wire they supply does not measure what it's labled. [ matthew   Aug 04, 2014 ]
  • I bought a 4 gauge wiring kit to go with it, and I'd works perfectly fine. The 4 gauge allowed plenty of power to flow through the amp with no distortion at all. [ Caleb   Aug 04, 2014 ]
Hi, I have an amp http://www.crutchfield.com/S-iZ7KycbdZts/p_500MRXM55/Alpine-MRX-M55.html and a sub http://www.crutchfield.com/S-W9DR1kXtuFR/p_500SWS1243/Alpine-SWS-1243D.html 1) the question is - how to wire them? Original thought was to run amp as 4 ohm @ 350W to 4 ohm sub @ 300W, but after some reading it is my understanding that only way to wire them is either at 2 or 8 ohm, parallel or series, 2) @ 2ohm the amp will output 550W to 300W sub, is it possible to tune it down, turn gain down or something? 3) if above doesn't work, would amp output 550W when head unit is turned all the way up? So if I turn it up half way, would it cause the amp to output ~275W ? 4) what will happen if I wire them as 8ohm? Thank you, Andrei. [ Andrei  Apr 08, 2014 ]
1 answer
  • If you purchased the product from Crutchfield, feel free to contact our Tech Support team. They can walk you through the install. Our toll-free Tech Support number is printed on your invoice, and is also available under the "My Orders" tab in the "My Account" section of our website. If you did not purchase the unit from Crutchfield, then you may want to contact the manufacturer. You can also post your question in our forums: http://community.crutchfield.com. Or try our online support center: http://crutchfield.custhelp.com/app/answers/list/kw/. [ Krissy Staff  Apr 08, 2014 ]

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For a more in-depth review and enhanced detailed information on the Alpine MRX-M55, please visit the Crutchfield website product page (/ISEO-rccbcspd/p_500MRXM55/Alpine-MRX-M55.html ).